Add binary datatype support for Postgres BYTEA

Waterline supports binary datatypes, so map them to BYTEA column
types in Postgres.  Convert buffers to hex strings (as per the
tradition in node-postgres) starting with \x, which will automatically
be converted back into Buffer objects when read from Postgres by
node-postgres.

See
https://github.com/brianc/node-postgres/issues/184
and
parseByteA of https://github.com/brianc/node-postgres/blob/master/lib/types/textParsers.js
Merge pull request #11 from Innovation-Toolkit/bytea-binary

Add binary datatype support for Postgres BYTEA
Fix adapter.define callbacks to prevent deadlock.

adapter.define and adapter.describe both try spawnConnection,
but adapter.define consumes all of the instances in the
pool (10, by default, in node-postgres) and thus the
adapter.describe function called at the end of adapter.define
results in deadlock (with very nasty effects to your database)
Merge branch 'bytea-binary' into bytea